From Audi 100 to urS4 in a week

[hunker7]

In first 3 gears it flies, do won't be the clutch

[igor136]

I'm kidding. But this is not the clutch.

[hunker7]

Another thing I've noticed. This time it went past 4000 rpm, some week ago I think I tried it, it didn't. So its not a constant problem.

[UrS4boy]

No, brakes are not sticky.

What does a clutch-in coast down feel like? Say you are driving on a flat (no up or down hills) empty 2 lane road at 80 kph, then take your foot off the gas and put the clutch in. How long does it take to drop to say 20 kph? Now repeat, but this time put the transmission in neutral and leave the clutch out. Does it slow down quicker than with the clutch in?

[hunker7]

I'll give it a shot sometime soon.

What am I finding out this way?

[UrS4boy]

I'll give it a shot sometime soon.
What am I finding out this way?

Whether the source of the drag is in the transmission. I am not convinced your brakes aren't dragging and this is one way to get you to find out how fast the car slows down on its own supposedly "without" brakes.

[hunker7]

Had calipers stripped down and rebuilt with new pads and discs. Transmission have been refurbished too. But I will do, just to be sure.

[bikerjim]

I haven't read all the details of the thread so I'm sorry if this has been covered already. When was the last time the fuel filter and air filter were changed? Also it might be worth checking the flow rate of the fuel at the rail? Like I said, sorry if its been covered before but hope it helps.

[hunker7]

I haven't read all the details of the thread so I'm sorry if this has been covered already. When was the last time the fuel filter and air filter were changed? Also it might be worth checking the flow rate of the fuel at the rail? Like I said, sorry if its been covered before but hope it helps.

Changed fuel filter, air filter isn't new, but checked and its fine. Haven't checked it, will do when I get back to London, but wouldn't that affect all gears/speeds?

[bikerjim]

Not really no. The biggest force acting against your road speed (velocity) is drag. The drag force increases exponentially with a linear increase in velocity. This is why it takes huge amounts of power to do 200+ MPH as opposed to 150 MPH. To make power you need fuel and air, so in higher gears when the car is really moving you need to consume a lot more fuel and air. In lower gears you do not have the drag acting on the car because you are not moving as fast, so you accelerate quickly, so if you had a fuel starvation problem it is more likely to show up at WOT in a high gear where fuel is being thrown into the engine for longer periods of time. If you have a week fuel pump you would likely see this occurring.

Hope that makes sense.

[hunker7]

Not really no. The biggest force acting against your road speed (velocity) is drag. The drag force increases exponentially with a linear increase in velocity. This is why it takes huge amounts of power to do 200+ MPH as opposed to 150 MPH. To make power you need fuel and air, so in higher gears when the car is really moving you need to consume a lot more fuel and air. In lower gears you do not have the drag acting on the car because you are not moving as fast, so you accelerate quickly, so if you had a fuel starvation problem it is more likely to show up at WOT in a high gear where fuel is being thrown into the engine for longer periods of time. If you have a week fuel pump you would likely see this occurring.

Hope that makes sense.

Spark plugs are quite black so I think it's running rich rather than lean (doing 50 mile ish drive in a minute, I'll check then again) What I will do, is check if there are any restrictions in air system, maybe IC is blocked?

[UrS4boy]

Not really no. The biggest force acting against your road speed (velocity) is drag. The drag force increases exponentially with a linear increase in velocity. This is why it takes huge amounts of power to do 200+ MPH as opposed to 150 MPH. .

I have attempted to explain this to the OP in this thread before and have posted the sketch below before, trying to explain why going a little faster needs more and more horsepower and why the rate acceleration decreases with increasing speed.

Maybe with your comments, it will start to sink in.

[hunker7]

So I got myself a new toy 195 000 miles, with FSH, 6 speed manual (obviously) It's 1993 comes with carbon trim, pre-select steel sunroof and from strut brace Rear shocks look Koni yellows Suspension is as solid as it gets really.





Problem I have is, it doesn't start. Immobilizer has packed up, it's been ripped out but still isn't working. Owner says the fuel pump runs when ignition is turned on, but when you try to start it, starter motor isn't engaging. This is how the immobilizer "key" looks like.



Maybe someone knows how these work, and where could I start with trying to get it revving?

First I want to see if starter motor is getting 12v, and signal from ignition.

[UrS4boy]

None of your photos are showing up.

And by "none" I mean NONE. Not just this recent post. ALL your posts. Ever.

[hunker7]

None of your photos are showing up.

Weird, I can see them